BATON ROUGE – It was against South Alabama but LSU football's dominant win inside Tiger Stadium Saturday night went down like a big spoonful of much-needed medicine for Brian Kelly and his team.

The Tigers' most complete game performance to date this season, they held a formidable duo in Jags' freshmen Fluff Bothwell and Gio Lopez on check pretty much all night while the offense, with junior Garrett Nussmeier throwing for a career-high in yards with 409, continued to slice and dice its way down the field all night.

LSU caps the nonconference portion of its schedule with the 42-10 win over South Alabama sitting 4-1 on the season and fades into an off week that Kelly has said will be treated as a game week rather than a recovery week.

Here are three pressing questions for the Tigers as a big SEC contest with rival Ole Miss awaits following the off week.

CONCERN FOR LSU AHEAD OF OLE MISS Where there is cause for concern for LSU football as big matchup with Ole Miss awaits

LSU-SOUTH ALABAMA GRADES Garrett Nussmeier hits 400 yards in LSU football's win vs South Alabama. Grading the win

Is LSU football's defense better without star linebacker Harold Perkins?

This is complex as there's no doubt that Harold Perkins is one of the best athletes and overall football players on LSU's roster. But the question is fair, considering how the defense looked in its first outing without him.

Kelly has mentioned a few times this season how Perkins has been trying to do too much and in those moments of trying to handle someone else's job would get lost on plays and be out of position.

Watching LSU's defense almost completely snuff out an electric Jags offense, they looked to be a more cohesive unit with guys only concerned about doing their one job of the full 11. So, in that regard, LSU's defense did play better without Perkins. But that's just at the surface.

There are things that Perkins can do at his position that no one else can in how he can cover backs, tight ends and receivers, how quickly he can affect the quarterback from various spots on the field as well as recover with his speed and instinct. Those are irreplaceable.

The competition ramps up with Ole Miss and Lane Kiffin making their way to Baton Rouge first as the Tigers will embark on seven straight SEC games, so we'll know better how much Perkins will be missed. But when players are out of position far less, there are fewer busted plays, and that's a positive for LSU.

What's LSU's biggest question ahead of Ole Miss matchup?

Everyone saw the Rebels go down at home to Kentucky and immediately thought that they aren't as good as they were perceived to be.

I think reality is more Mark Stoops' Kentucky is just simply a bad matchup for Ole Miss. Kentucky is scary good on the interior defensive line with Deone Walker, a first-round NFL Draft pick and they have really good cover guys on the perimeter.

What the Wildcats did well, that I believe is LSU's biggest question ahead of the game with Ole Miss, is tackling. Kentucky tackled so well, especially in open space that the Rebels couldn't turn those shorter plays into bigger ones like they're known to do.

LSU did tackle better against South Alabama but Ole Miss will have far better athletes at every position. LSU has struggled tackling this season, and it can't afford to not tackle well against Kiffin's group, or it'll be in for a long night.

What happened to LSU running back Kaleb Jackson?

The thought coming into the year was that sophomore Kaleb Jackson was going to be the primary backup tailback to Josh Williams and that he would be logging plenty of snaps. He ended his freshman season on a tear, and the LSU coaches love how he runs the ball with power and physicality.

He gained 35 pounds in the offseason to be able to handle more of a load this season.

What's been keeping Jackson off the field has been the emergence of freshman Caden Durham. While the offense was trying to find a tailback that could do the things they were asking of them in the first four weeks of the season, Durham flashed to be the one that had what they were looking for in patience and vision and the ability to make tacklers miss in open field.

It's what LSU's offense needs more of right now, and that's not Jackson's game.

LSU WINS CONVINCINGLY OVER JAGUARS LSU football blows out South Alabama behind Garrett Nussmeier's career night

BRIAN KELLY Brian Kelly offers idea for clearing up playoff bubble, but will CFP committee listen?

Cory Diaz covers the LSU Tigers for The Daily Advertiser as part of the USA TODAY Network. Follow his Tigers coverage on Twitter: @ByCoryDiaz. Got questions regarding LSU athletics? Send them to Cory Diaz at bdiaz@gannett.com.

This article originally appeared on Lafayette Daily Advertiser: LSU mailbag: Is LSU football's defense better without Harold Perkins?